Specifications
| Fuel | Diesel |
|---|---|
| Frequency | 50.0 Hz |
| Standby power | 2 kW |
| Standby kVA | 2 |
| Controller | Analog control panel: battery charge rate ammeter, preheat switch, start-stop switch, field circuit breaker |
| Oil capacity | 3.0 L |
| Voltage options | 120 V, 240 V, 120/240 V |
| Phase | 1 |
| Power factor | 1.0 |
| Battery group | 1H |
| Battery cranking | 450 CCA |
| Battery voltage | 12 V |
| Battery quantity | 2 |
| Dimensions (L×W×H) | 727×524×681 mm |
| Dry weight | 166 kg |
Maintenance & consumables
for the Cummins/Onan MDJA| Item | Spec | Capacity | Part # | Interval | |
|---|---|---|---|---|---|
| Air filter | Engine air intake filter | — | find | ||
| Fuel filter | Secondary fuel filter | — | 3000 hr | find | |
| Oil filter | Spin-on oil filter; adds 1.0 pint (.47L) beyond base oil capacity | — | 200 hr | find | |
| Coolant | Optional heat-exchanger (captive water) cooling system capacity; 50/50 ethylene glycol/water mix recommended | — | |||
| Oil | Crankcase oil, API CD/SE (CC/SE for first 50-hour fill only); use SAE grade per ambient-temperature chart | — | 100 hr |
Common questions
What is the power rating of the Cummins/Onan MDJA?
The Cummins/Onan MDJA is rated 2 kW standby (2.5 kVA).
What engine does the Cummins/Onan MDJA use?
The Cummins/Onan MDJA is powered by the Cummins/Onan MDJA engine.
What fuel does the Cummins/Onan MDJA use?
The Cummins/Onan MDJA runs on Diesel.
What is the oil capacity of the Cummins/Onan MDJA?
The Cummins/Onan MDJA engine in the Cummins/Onan MDJA has an oil capacity of 2.4 liters.
Troubleshooting
22Symptoms & remedies
| Symptom | Cause | Remedy |
|---|---|---|
| TAPPING SOUND | Poor grade or dirty fuel. Injection pump or nozzle not operating properly. Faulty injection timing. Dirty air cleaner. Fuel tank empty. Safety switch operated (where used). Loose crankshaft bearing. Low oil supply. Oil badly diluted. Valve clearance too great. Broken valve spring. | Use only clean, recommended fuel. Clean nozzle. If necessary, install new nozzle or injection pump. Check injection pump timing. Clean. Refill. Correct the overheating or the lubrication failure. Press reset switch. Replace unless one of the next two remedies permanently corrects the trouble. Add oil. Change oil. Adjust. Replace faulty valve system. Install new spring. If noise only slight and disappears when engine warms up, no immediate attention needed. Otherwise replace worn parts. Adjust or replace. |
| ENGINE RACES | Too much fuel injected. Faulty injection. | Check governor performance and linkage condition. |
| ENGINE MISFIRES | Low compression. Defective gauge. Oil too light or diluted from leaking fuel pump diaphragm. Oil too low. Oil relief valve not seating. Badly worn bearings. Sludge on oil cup screen. Badly worn oil pump. | Tighten cylinder head. Service valves and piston rings as needed. Replace. Drain. Refill with proper oil. Repair or replace transfer pump. Add oil. Clean. Replace if needed. Replace. Clean screen and oil sump. Replace. |
| LOW OIL PRESSURE | Oil too light or diluted from leaking fuel pump diaphragm. Oil too low. Oil relief valve not seating. Badly worn bearings. | Drain. Refill with proper oil. Repair or replace transfer pump. Add oil. Clean. Replace if needed. |
| HIGH OIL PRESSURE | Oil too heavy grade. | Change oil. |
| ENGINE OVERHEATING | Clogged oil passages. Oil relief valve stuck. Poor coolant circulation. | Clean all lines and passages. Clean by-pass. Replace if needed. |
| VOLTAGE LOW AT FAR END OF LINE BUT NORMAL NEAR POWER PLANT | Too small line wire for load and distance. | Install larger or extra wires or reduce load. |
| ELECTRIC MOTOR RUNS TOO SLOWLY AND OVERHEATS AT FAR END OF LINE BUT OK IF USED NEAR POWER UNIT | Too small line wire for load and distance. | Install larger or extra wires or reduce load. |
| VOLTAGE UNSTEADY BUT ENGINE NOT MISFIRING | Speed too low. Poor brush contact (or poor commutation on revolving armature models). Loose connections. Fluctuating load. | Adjust governor to correct speed. See that brushes seat well on commutator, are free in their holders, are not worn too short, and have good spring tension. Tighten connections. Correct any abnormal load condition causing trouble. |
| NOISY AND EXCESSIVE ARCING OF BRUSHES (REVOLVING ARMATURE MODEL) | Rough commutator. Dirty commutator. Brushes not seating properly. | Turn down. Undercut mica between bars. Clean. Sand to a good seat. |
| GENERATOR OVERHEATING (APPROXIMATELY 160°F. HIGHER THAN AMBIENT) | Overloaded. | Reduce load. |
| VOLTAGE DROPS UNDER HEAVY LOAD | Poor compression. Faulty injection. Dirty air cleaner. Restricted exbaust line. | Tighten cylinder head and spark plug. If still not corrected, grind the valves. Replace piston rings, if necessary. Check the fuel system. Clean, adjust or replace parts necessary. Clean. |
| ENGINE WILL NOT CRANK | Battery discharged. | Recharge. |
| ENGINE WILL NOT START WHEN CRANKED | Defective starting circuit. | Repair or replace as necessary. |
| ENGINE STOPS WHEN START SW. IS RELEASED | Too heavy oil in crankcase. | Drain, refill with lighter oil. |
| ENGINE RUNS BUT VOLTAGE DOES NOT BUILD UP | Poor brush contact. | See that brushes seat well, are free in their holders, are not worn too short, and have good spring tension. |
| EXCESSIVE OIL CONSUMPTION, LIGHT BLUE SMOKY EXHAUST | Oil leaks from oil base or connections. | Drain, refill with correct oil. |
| BLACK, SMOKY EXHAUST, EXCESSIVE FUEL CONSUMPTION, POSSIBLE LOW POWER UNDER HEAVY LOAD | Poor compression, usually due to worn piston, rings, or cylinder. | Repair as necessary. |
| ENGINE STOPS UNEXPECTEDLY | Black smoky exhaust normal condition with overload. | Reduce load to within rated capacity. If smoky condition continues, stop unit and investigate. |
| DULL METALLIC THUD. IF NOT BAD, MAY DISAPPEAR AFTER FEW MINUTES OPERATION. IF BAD, INCREASES WITH LOAD. | Tighten cylinder head, grind or replace valves, replace piston rings as needed. | |
| SHARP METALLIC THUD | Refer to symptoms of engine misfiring. | |
| Do not work on energized equipment | Do not work on energized equipment. Unauthorized personnel must not be permitted near energized equipment. Induced voltage remains even after equipment is disconnected from the power source. Plan maintenance with authorized personnel so equipment can be de-energized and safely grounded. |
Fault codes and symptom→remedy steps extracted from this model’s service/owner documentation; verify against the official manual before servicing.
Parts
13| Part # | Description | Qty | System | |
|---|---|---|---|---|
| 122-0185 | Oil Filter MDJA, MDJB, MJC, MDJE, MDJF, MJA, MJB, MJC | Oil filter | Amazon eBay $24.99 PartsGeek | |
| 122-0325 | Fuel Filter Element PRIMARY MDJA (Spec A–R), MDJB (Spec A–R), MDJC (Spec A–R), MDJE (Spec A), MDJF (Spec A) | Fuel filter | PartsGeek | |
| 122-0326 | Fuel Filter Element SECONDARY MDJA (Begin Spec S), MDJB (Begin Spec S), MDJC (Begin Spec S), MDJE (Begin Spec B), MDJF (Begin Spec B) | Fuel filter | PartsGeek | |
| 130-1340 | Zinc Pencil MDJA, MDJB, MDJC, MDJE, MDJF, MDTA, MJA, MJB, MJC | Zinc pencil | PartsGeek | |
| 130-4961 | Zinc Pencil MDJA, MDJB, MDJC, MDJE, MDJF, MDTA, MJA, MJB, MJC | Zinc pencil | PartsGeek | |
| 132-0110 | Fresh Water Pump - With Metal Impeller | 1 | Pump | PartsGeek woodline $1907.68 |
| 132-0133 | Fresh Water Pump - With Keel Cooler Kit | Pump | PartsGeek | |
| 149-0428 | Fuel Filter Element MDJA (Spec A–R), MDJB (Spec A–R), MDJC (Spec A–R), MDJE (Spec A), MDJF (Spec A) | Fuel filter | PartsGeek | |
| 309-0156 | Thermostat | Switch | PartsGeek | |
| 333-0106 | Glow Plug MDJA, MDJB, MDJC, MDJE, MDJF (12 Volt) | Glow plug | PartsGeek | |
| 4028328 | Bushing, DJA, MDJA | 1 | Bushing | PartsGeek |
| 155-0950 | Siphon Break Kit (prevents sea water siphoning into engine when exhaust injection elbow is below load waterline) | 1 | Service part / kit | PartsGeek |
| 308-0155 | Part 308-0155 | 1 | Service part / kit | PartsGeek |
Service, wear & replacement parts referenced for this model and its engine — confirm the exact part for your serial number. See the full parts catalog to search and cross-reference.
Fuel consumption
| Rating | Load | L/h | gal/h |
|---|---|---|---|
| Prime | |||
| Standby |
Available documents
Parts manual — DK-Kohler (Cummins/Onan)Parts manual — NET-Onan (Cummins/Onan)Service manual — 968-06xx MDJA MDJB MDJC Installation Manual (Cummins/Onan)